Safety apparatus for petroleum wells

ABSTRACT

Safety apparatus for petroleum wells, particularly wells located offshore, wherein the apparatus has means for quickly and positively closing off fluid flow from the well in the event of a well fire, blowout or similar dangerous well condition.

Phi-1on1 Mates Patent Inventors Maurice Kirkpatrick 1734 lBriarbendl;

Donnell E. Waggener, 5035 Ynrwell, both 01 Houston, Tex. 77035 Appl. No. 41,788

Filed June 1, 19711 Patented Dec. 21, 1971 SAFETY APPARATUS IFOR PETROLEUM WELILE 11 Claims, 5 Drawing Figs.

11.5. C1 166/226 llnt. C1....... .12211 33/011 ll ielrl of Search 166/226,

Primary ExaminerJames A. Leppink Attorney-Havel, Wilson & Matthews ABSTRACT: Safety apparatus for petroleum wells, particularly wells located offshore, wherein the apparatus has means for quickly and positively closing off fluid flow from the well in the event ofa well fire, blowout or similar dangerous well condition.

SAFETY APPARATUS FOR PETROLEUM WELLS BACKGROUND OF THE INVENTION The field of this invention is safety apparatus for petroleum wells.

In recent months, one of the most threatening and dangerous problems of the offshore petroleum industry has been petroleum well fires, blowouts and other occurrences which have resulted in unintentional loss of oil from the well, causing contamination and pollution of the water and the shore areas reached by the oil. The difficulties have become so severe that offshore production has been curtailed in some instances, and further curtailment is considered a possibility, which has, and could further, materially damage the entire offshore petroleum industry.

SUMMARY OF THE INVENTION the present invention relates to a safety apparatus which is positioned in an offshore petroleum well string so that, under normal circumstances, the petroleum production proceeds in the usual manner through the pipe string and the safety apparatus therewith, but upon the occurrence of a fire, blowout or other uncontrolled loss of petroleum from the well, the safety apparatus may be actuated at the well site or at a point remote therefrom, so as to completely out off the flow of petroleum through the pipe string to thereby kill the fire and prevent loss of the petroleum from the well.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a vertical sectional view, partly in elevation, of one form of the present invention;

FIG. 2 is an enlarged sectional view taken on line 22 of FIG. I to illustrate a portion of the apparatus of FIG. I, with the apparatus in the opened position for fluid flow through the pipe string;

FIG. 3 is a view similar to that of FIG. 2, but illustrating the apparatus in the closed position, wherein fluid flow through the pipe string is cut off;

FIG. 4 is a vertical sectional view, partly in elevation, illustrating a modification of the form of the invention illustrated in FIGS. 1-3, with the apparatus being shown in the open position for fluid flow through the pipe string with which the apparatus is connected; and

FIG. 5 is a view of the form of the invention illustrated in FIG. 4, but showing the apparatus in the closed position.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the drawings, the letter A designates generally the apparatus of this invention in the form illustrated in FIGS. 1-3. Such apparatus A is disposed in a well casing C or other well pipe, in which a tubing or pipe string P is disposed. The apparatus A is connected to the tubing or pipe string P (FIG. I) and normally, such string P extends through a conventional well packer or seal S which is disposed between the tubing T and the casing C. The apparatus A extends upwardly through a wellhead assembly W, a portion of which is schematically illustrated in FIG. I, which is generally disposed at the platform or derrick floor F, which is above the water level in an offshore well location. As will be explained, the apparatus A normally is positioned in the pipe string P, thus forming a part thereof, so that normal production or flow of petroleum, either oil or gas, occurs through the pipe string P and the apparatus A. However, in the event of a fire, blowout or other occurrence requiring the closing off of the well, at least temporarily, the apparatus A can be immediately actuated so as to obtain a positive closure or cutoff of the petroleum flow from the well through the pipe string P, thereby cutting off the source of any well fire or blowout through the pipe string P.

Considering the invention more in detail, and particularly the apparatus A illustrated in FIGS. 1-3, such apparatus A includes a first or upper tubular member T-I, and a lower or second tubular member T-Z which are normally in an extended position (FIG. 2) for the normal flow of petroleum therethrough, but which are positioned for longitudinal telescoping movement towards each other to a closed position (FIG. 3) for closing off such flow of petroleum therethrough.

Although the tubular member T-I is illustrated in the drawings as formed of several components or parts, it may be considered as a single member since the components or parts are connected together and function together. The same is true with respect to the tubular member T-2. Thus, the tubular member T-I has a reduced diameter tube or pipe I0 therewith near its lower end which carries a lower flow tube adapter II having an inclined passage or port llIa therethrough. A disc 112 formed of rubber or other resilient material is disposed at the lower end of the adapter II and is secured thereto by any suitable means such as an epoxy resin. The rubber disc I2 has a port 112a therethrough which is in alignment with and forms a continuation of the passage 11a.

The first tubular member T-I extends upwardly from the tube or pipe I0 by means of one or more sections of tubing or pipe 14 which are threaded or are otherwise connected to the upper end of the tube 10. The tubing M may be of the same or a different diameter than the tube I0. The tubing I4 extends upwardly through the wellhead W (FIG. I) and into a cylinder I6, forming a part of a support assembly B for supporting the apparatus A.

Thus, the support assembly B includes a flange I7 connected at the lower end of the cylinder I6, having a longitudinal passage 17a therethrough, with a seal 171; such as a standard resilient rubber O-ring which is in sealing engagement with the external surface of the pipe string M. The flange 17 has a port I7c communicating with a fluid inlet line 13 having a valve I811 therewith so as to control [hydraulic fluid or other fluid flow into and out of the cylinder I6, as will be more evident hereinafter.

A pair of longitudinally spaced members 20 and 21 are secured to the upper end of the pipe string I4 so as to provide a recess or annular space 22 therebetween. Preferably, the lower member 20 is a piston which is annular in construction and which has an annular seal 20a therewith, such as the conventional O-ring made of rubber or other material, which is in sealing engagement with the inside surface of the cylinder 16 and the extension thereof within a support head 26 connected at the upper end of the cylinder I6.

One or more releasable laterally movable support rods 26 are slidably disposed in the support head 25, with an annular seal 26a disposed externally thereof to prevent fluid within the cylinder 16 from escaping. The rods 26 are movable inwardly and outwardly relative to the member 21, which is preferably in the form of a ring so that when the rod or rods are in the inward position (FIG. 1), the members 21 rest thereupon to thereby support the entire apparatus A within the well casing C The rods 26 are each mounted for movement, using any source of power such as a piston 26b mounted in a cylinder 27 and which is supplied with hydraulic fluid or other suitable fluid through fluid lines 27a and 27b.

The upper end of the support head 25 is closed off by any suitable means such as a cap 30 which is bolted or otherwise secured to the rest of the structure and which has therewith a seal ring or packing 3011 which engages the external surface of the portion of the tubing string I41 extending above the member 2I.

The second tubular member T-2 (FIGS. 2 and 3) includes an outer sleeve or pipe 35 which has: means for mounting a packing 36 at its inner portion near its upper end for sealing engagement with the external surface of the tube 10. Although the packing 36 may be mounted in any suitable way in the upper end of the sleeve 35, it is shown in the drawings as being mounted on a lower ring 36a which is threaded into the interior of the sleeve 35 and it is compressed by a threaded packing nut 36b so that the packing 36 may be squeezed to effect an adjustable seal with the external surface of the tube II). It should also be noted that upon a removal of the ring 360, the

packing 36 and the packing gland 36b, the tubular members T-l and T-2 may be separated from each other. Also, the lower end of the tube is threaded or is otherwise releasably connected to the flow tube adapter Ill so that they may be separated if it is desired to replace the adapter 11 and/or the seal element 12 therewith.

Under normal operating conditions, the sleeve 35 is releasably connected to the adapter II by a shear pin 37 so that the tubular members T-l and T-2 are held in the extended position of FIG. 2. However, as will be more fully explained, upon a shearing of the pin 37, the members T -l and T-2 may move longitudinally relative to each other to effect a closing off of the fluid flow.

For this purpose, the lower tubular member T-2 is formed with an offset passage 38a in a special section 38 connected with or formed as a part of the sleeve 35. The passage 38a is preferably inclined or is otherwise formed so that its upper end is offset laterally with respect to the lower end of the passage Ila. A sealing disc or seal element 40 formed of rubber or other suitable resilient material and having a passage 40a therethrough is mounted on the upper end of the section 38, with the passage 40a forming a continuation of the passage 38a, and likewise being offset from the passage 12a. The section 38 is connected by threads 38b or other suitable means to the remainder of the pipe string P therebelow which extends down through the packer S to the well formation which is producing the petroleum, in the known manner.

In the use or operation of the apparatus A of the present invention, it is positioned at the upper end of a pipe string P which extends down to a well formation (not shown). The apparatus A is suspended in the wellhead W by the support rods 26 which engage below the support member 21 (FIGS. 1 and 2). In the position illustrated in FIG. 2, the tubular members T-l and T-Z are in the extended position for the normal flow of oil or other petroleum products through the pipe string P and the apparatus A for discharge at any suitable point at the surface above the platform F.

Should a tire, blowout or other similar occurrence take place, the hydraulic fluid is admitted to the cylinders 27 through the flow tubes 27b to force the pistons 26b laterally outwardly from the position shown in FIG. 1 so that the rods 26 move outwardly and no longer support the member 21, whereby the entire assembly A is free to drop by its own weight in the casing C.

If there is hydraulic fluid or other fluid within the cylinder 16, the valve 18a must also be opened at that time to permit the apparatus A to fall. On the other hand, it will normally be preferable to leave the valve 181: open during normal operations so that only the pins or rods 26 will have to be moved in order to release the support for the apparatus A and allow it to drop from the position shown in FIG. 2 to the position shown in FIG. 3.

Upon a release of the apparatus A from its support through the pins 26, the shear pin 37 is sheared due to the weight of the apparatus acting thereon and that allows the tubular member T-l to move downwardly relative to the tubular member T-2 so that the sealing disc or seal elements 12 and 40 move into sealing engagement with each other (FIG. 3). It is to be noted that the offset position of the passages 11a and 38a makes it possible to seal them or close them to flow when the closure members or seals 12 and 40 are in the position of sealing shown in FIG. 3.

After the flre has been put out, and the well has been otherwise brought under control, the apparatus A may be raised to return it from the position shown in FIG. 3 to the position shown in FIG. 2 by introducing fluid under pressure through the valve 18a and the line 18 into the passage 17c and the interior of the cylinder 16 below the piston 20. Such hydraulic pressure is sufficient to force the piston 20 to move upwardly within the cylinder 26 to the position shown in FIG. 1, whereupon hydraulic fluid or other fluid is introduced through the flow tubes 27!: into the cylinders 27 for forcing the pistons 26b inwardly to reposition the rods 26 below the support member 21 (FIG. 1). Thus, the apparatus A is again in position for fluid flow from the well formation upwardly through the entire apparatus A to the upper end of the tubing or pipe 14 for discharge to any suitable point at ground level. The safety apparatus of this invention is thus ready for use again as needed, and it may be used as often as needed, providing damage thereto does not occur from any abnormal circumstance.

In FIGS. 4 and 5, a modified form of the invention is illustrated wherein tubular members T-3 and T-4 correspond with the tubular members T-l and T-2, respectively, of FIGS. 1-3. The upper end of the tubular member T-3 is connected to a pipe or tube 114 which corresponds with the pipe or tube 14 and it extends upwardly and is supported in the same manner as illustrated in FIG. I.

The tubular member T-3 has a longitudinal flow passage 50 therethrough which is in line with the opening or passage in the tubing or string 114 thereabove. The lower tubular member T-4 includes a pipe or tube 51 which is slidable within the passage 50 of the member T-3 and which also has a longitudinal passage therethrough which is aligned with passage 50 and the pipe string P therebelow.

The tubular members T-3 and T-4 are releasably connected together in the extended position (FIG. 4) by a shearpin 52 which is adapted to be sheared when the support for the apparatus A at the upper end of the tubular member T-3 is released, as explained heretofore in connection with FIG. 1.

For closing off the flow of fluid through the assembly A-] of FIGS. 4 and 5, a closing mechanism is provided including a ball 55 which is supported on a movable rod 56 having a head 56a at its upper end. The rod 56 is connected to the lower pipe string P or the tubular member T4 so that it is supported thereby. Preferably, the ball 55 is attached to the head 56a by a flexible line 57 which may be welded to the ball 55 and also to the head 56a or otherwise suitably attached.

The rod 56 and the ball 55 are disposed in a separate cylinder or chamber 60 which is welded or is otherwise attached to the external surface of the tubular member T-3. The chamber or cylinder 60 has an open upper end 60a which permits the ball 55 to move upwardly for seating engagement in a valve seat 50a in the passage 50 so as to close off fluid flow through the entire apparatus A-l (FIG. 5). Normally, the valve element or ball 55 cannot reach the valve seat 50a when the tubular members T-3 and T-4 are in the extended position (FIG. 4) and therefore the closure element or ball 55 does not interfere with the normal petroleum production through the apparatus A-l.

However, when the support means for the apparatus A-l, such as that illustrated in FIG. 1, is released, the tubular member T3 moves downwardly relative to the tubular member T-4, which causes the upper end 60a of the cylinder 60 to move downwardly relative to the ball 55, and once the ball 55 is exposed to the fluid pressure flowing through the passage 50, the fluid pressure carries the ball upwardly and forces it into the seat 500 (FIG. 5). Upon seating therein, the ball 55 prevents further flow through the passage 50 and the rest of the apparatus Al. If the cable or line 57 is utilized as indicated in the drawings, the apparatus A-l may be returned from the telescoped position of FIG. 5 to the extended position of FIG. 4 by lifting the upper tubular member T3 relative to the lower tubular member T-4, utilizing the piston 20 and cylinder 16 of FIG. I, or any other suitable lifting mechanism. The upper end of the tubular member T-3 is again supported by the support assembly such as that illustrated in FIG. 1 so as to return the apparatus A-l to the position of FIG. 4. It is to be noted that the cable or wire 57 pulls the ball 55 back into the cylinder or chamber 60 so that it no longer is affected by the fluid flow through the passage 50. Thus, the apparatus A-I may be utilized once, for closing off fluid flow in the event of a fire, blowout or other similar current, or it may be utilized repeatedly for such safety purposes.

The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape, and materials as well as in the details of the illustrated construction may be made without departing from the spirit of the invention.

We claim: ll. Safety apparatus for use in a petroleum well having a well casing and a wellhead assembly therewith, comprising:

a first tubular member adapted to be disposed in a well casing', support means for releasably supporting said first tubular member in a wellhead assembly at the upper end of the well casing; a second tubular member having means therewith for connection to a tubing string therebelow; said tubular members being normally in an extended position and adapted for longitudinal movement towards each other; said tubular members having passages therethrough which are laterally offset with respect to each other and which are in communication with each other when said members are in the extended position; and closure means including a seal on each of said tubular members for closing off the flow through said passages upon a movement of said first tubular member longitudinally towards said second tubular member; each said seal being a resilient disk having a surface for covering the passage in the other tubular member. 2. The structure set forth in claim 1, including: releasable connecting means for normally securing said tubular members together in the extended position. 3. The structure set forth in claim 1, wherein: each said resilient disk has a substantially flat external surface for said covering of the passage in the other tubular member. 4. The structure set forth in claim 1, including: operating means for effecting a release of said support means. 5. The structure set forth in claim 1, including: means for lifting said first tubular member back to its extended position after said support means has been released and said members have telescoped longitudinally for reconnecting said support means to thereby reestablish normal fluid flow through said tubular memtil bers. 6. The structure set forth in claim 1, wherein said support means includes:

a locking head at the upper portion of said first tubular member;

a locking pin operably disposed with said wellhead assembly for releasable engagement with said locking head; and

operating means for moving said locking pin into and out of locking engagement with said locking head.

7. The structure set forth in claim 6, including:

control means for said operating means disposed remotely from said wellhead assembly for facilitating a closure of fluid fiow through said tubular members and the pipe string therewith in the event of a fire or the like at the well.

8. Safety apparatus for use in a petroleum well having a well casing and a wellhead assembly therewith, comprising:

a first tubular member adapted to be disposed in a well casing;

support means for releasably supporting said first tubular member in a wellhead assembly at the upper end of the well casing;

a second tubular member having means therewith for connection to a tubing string therebelow;

said tubular members being normally in an extended position and adapted for longitudinal movement towards each other;

said tubular members having passages therethrough and in communication with each other when said members are in the extended position;

closure means for closing off the flow through said passages upon a movement of said first tubular member longitudinally towards said second tubular member; and said closure means including:

a ball;

a pocket formed in said first tubular member;

means for normally retaining said ball in said pocket; and means for causing said ball to move to the closing-off position, including a pusher assembly connected to said second tubular member and longitudinally movable in said first tubular member. 

1. Safety apparatus for use in a petroleum well having a well casing and a wellhead assembly therewith, comprising: a first tubular member adapted to be disposed in a well casing; support means for releasably supporting said first tubular member in a wellhead assembly at the upper end of the well casing; a second tubular member having means therewith for connection to a tubing string therebelow; said tubular members being normally in an extended position and adapted for longitudinal movement towards each other; said tubular members having passages therethrough which are laterally offset with respect to each other and which are in communication with each other when said members are in the extended position; and closure means including a seal on each of said tubular members for closing off the flow through said passages upon a movement of said first tubular member longitudinally towards said second tubular member; each said seal being a resilient disk having a surface for covering the passage in the other tubular member.
 2. The structure set forth in claim 1, including: releasable connecting means for normally securing said tubular members together in the extended position.
 3. The structure set forth in claim 1, wherein: each said resilient disk has a substantially flat external surface for said covering of the passage in the other tubular member.
 4. The structure set forth in claim 1, including: operating means for effecting a release of said support means.
 5. The structure set forth in claim 1, including: means for lifting said first tubular member back to its extended position after said support means has been released and said members have telescoped longitudinally for reconnecting said support means to thereby reestablish normal fluid flow through said tubular members.
 6. The structure set forth in claim 1, wherein said support means includes: a locking head at the upper portion of said first tubular member; a locking pin operably disposed with said wellheaD assembly for releasable engagement with said locking head; and operating means for moving said locking pin into and out of locking engagement with said locking head.
 7. The structure set forth in claim 6, including: control means for said operating means disposed remotely from said wellhead assembly for facilitating a closure of fluid flow through said tubular members and the pipe string therewith in the event of a fire or the like at the well.
 8. Safety apparatus for use in a petroleum well having a well casing and a wellhead assembly therewith, comprising: a first tubular member adapted to be disposed in a well casing; support means for releasably supporting said first tubular member in a wellhead assembly at the upper end of the well casing; a second tubular member having means therewith for connection to a tubing string therebelow; said tubular members being normally in an extended position and adapted for longitudinal movement towards each other; said tubular members having passages therethrough and in communication with each other when said members are in the extended position; closure means for closing off the flow through said passages upon a movement of said first tubular member longitudinally towards said second tubular member; and said closure means including: a ball; a pocket formed in said first tubular member; means for normally retaining said ball in said pocket; and means for causing said ball to move to the closing-off position, including a pusher assembly connected to said second tubular member and longitudinally movable in said first tubular member. 